How to Identify and Treat Dog Eye Problems

"Dog eye problems are fairly common and can result in symptoms ranging from mild irritation or conjunctivitis to blindness, ocular tumors and eye loss. The top three eye diseases in dogs are corneal abrasions, keratoconjunctivitis sicca (canine dry eye) and glaucoma. The cornea is the outermost layer of the eye, so it is subjected to injury from normal dog behaviors such as exploring when outdoors. Bacterial infections of the conjuncytiva or cornea (conjunctivitis and keratitis respectively) will cause eye redness, and mucous eye discharge, Canine conjunctivitis will also cause swollen eyelids and excessive redness inside of the eyelid. Canine eye injuries such as corneal ulcerations or abrasions will cause excessive watering and eye pain. Dry eye in dogs causes a thick string like mucous across the eye. If not corrected, it causes melanin pigment to be deposited in the cornea causing corneal inflammation. Each of these and other less common conditions are described and pictured below. If your dog is showing any signs of pawing at the eyes, eye pain, squinting, watery eyes, enlarged eyes or any mucous discharge, see a veterinarian as soon as possible. When it comes to the eyes, any delays could result in blindness or the need to remove the eye."

Eye problems in dogs are a common occurrence. Dog eye health issues can be suspected based on observation. Use your thumb to pull the upper eyelid so you can get a better view of the eye. The white area (sclera) should glisten white with very thin red blood vessels. Higher up on the edge of the eye is pink tissue called the conjunctiva. In a healthy dog eye, the dog conjunctiva color should match the color of the dog's gums.

Signs of dog eye problems include blood vessels that look engorged, any bruises around the eye or a sclera which is yellow (could be dog jaundice), and discharge such as mucous.

Dog eye diseases are classified by being external, affecting the eyelids, conjunctiva, cornea and sclera (common) or internal such as canine uveitis, which refers to inflammation of the inner eye (less common).

Common External Dog Eye Diseases:

Canine Conjunctivitis: Conjunctivitis in dogs is caused by a bacterial infection of the conjunctiva. Symptoms include swollen eyelids, redness inside of the eyelid, mucous discharge and dog eye redness.

Keratitis: Caused by bacterial infection of the cornea. Symptoms include dog eye redness and mucous discharge.

Dog eye injuries (corneal ulcer, abrasion): Symptoms include excessive watering and pain such as eye squinting and rubbing with a paw.

Dog Dry Eye: Caused by a tear gland problem or malfunction. Dry eye in dogs (also called keratoconjunctivitis sicca) results in an overabundance of thick stringy mucous across the eye. Can also cause a secondary condition where melanin pigment is deposited in the cornea.

Less Common Internal Dog Eye Diseases: these types of canine eye disorders tend to be more severe and often threaten a dog's vision and eye integrity.

Canine Uveitis: This canine eye condition refers to inflammation of the inner eye. The dog iris or inside of the eye will have a reddish tint.

Canine Glaucoma: Glaucoma
in dogs is caused by
increased eye pressure inside the eye. May have multiple
underlying causes. You'll notice eye enlargement from the pressure.

Normal Dog Eye Anatomy

Dog Eye Health - Normal Canine Eye Anatomy

The
pictures in this section are reprinted with permission
by the copyright owner, Hill's Pet Nutrition, from the Atlas of
Veterinary Clinical Anatomy. These illustrations should not be
downloaded, printed or copied except for personal, non-commercial use.

Healthy
dog eyes take care of themselves with tears which flush out the eye,
and nasolacrimal ducts which help them drain. If your dog's eyes are
healthy, owners only need to watch for any problems. During regularly
scheduled checkups your vet will check the condition of the eyes, and
use an opthamlmoscope to examine the retinas. The exam will also help
to detect problems early such as canine cataracts, dry eye, and eye
cancer.

The eye is also a window into other diseases in the body. For example,
dog diabetes is one of the causes of cataracts.

Dog Eye Anatomy
Source: Washington State University

Dog Eye Conditions and Diseases

Dog Cataracts

Dog
cataracts describes a condition where the lens inside the eye
is starting to
become cloudy, making vision difficult for your pet.

The condition is common in certain breeds or is a result of another
condition such as diabetes, eye injury or inflammation that is
occurring in the eye. Treatment involves surgical removal of the cloudy
lens. The prognosis for achieving better sight is excellent. You will
have to administer eye drops for several weeks after the surgery.

There is some talk that eye drops can actually cure cataracts.
According to the American Academy of Veterinary Ophthalmologists, there
is no accepted evidence in the scientific community supporting this
claim.

Dog's with cataracts are also often checked for dog
diabetes, since this is a major cause of the condition.
Diabetes, if left untreated, allows sugar to build up inside the eye
lens, which causes water to be pulled into the lens. The lens
then swells and breaks up the lens fibers, which results in cataracts.

Dog Cherry Eye

The condition known as dog
cherry eye occurs when the tear glands behind your dog's
third
eyelid moves out of position, which is called prolapsed gland of the
third eyelid.
Since this gland provides your dog's tear production, it is important
to ensure that the condition does not cause tear production to stop.
Dog cherry eye is not painful Surgery has a high rate of success and is
used to create a pocket for the gland which is then put back into
position.
If left untreated it can hurt your dog's eye health causing dry eye,
irritation and if rubbed, bleeding, irritation and possibly
infection.

Dog Cherry EyeProlapse of the gland of the third eyelid in a BeagleSource: Washington State University

Canine Corneal Ulcer

The first line of defense against injury and bacteria is the cornea, which is a transparent outer layer. Because it is the outermost surface, it is more likely to be injured than other parts of the eye from foreign objects, particularly those found outdoors or even eyelashes.

Dog eye
scratches or corneal
ulcers or abrasions can cause symptoms such as squinting,
pain, watery eyes and red eyes. Minor dog eye scratches will heal on
their own. Treatment for deeper abrasions or corneal ulcers are
diagnosed in a veterinarian's office using a green stain
named flourescein that clings to any abrasion. Treatment depends on the
severity of the injury.
Mild corneal abrasions are treated with topical antibiotics and if
needed, pain medications. Severe cases may require surgical grafts in
order to save the dog's eye.

Canine Distichiasis

Canine distichiasis is a condition where glands that do not normally
grow eyelashes start to grow them. Since the eyelashes are out of
position, they could irritate the eye causing irritation, inflammation
and possibly a corneal ulcer (eye wound). Treatment is only necessary
if it is bothering your dogs eye and could include trimming the
eyelashes, plucking them, electrolysis or surgical removal of the hair
follicle. Even with these techniques, new hair follicles and eyelashes
could form impacting your dog health eye.

Canine Entropion

Dog
entropion is a condition where the eyelid rolls back into the
eye. It is an inherited condition in younger dogs and or due to
weakening muscles in older dogs. Treatment involves a surgical
procedure.

Picture of Dog Entropion

Canine
Glaucoma

Dog
glaucoma is a condition where fluid in the eye doesn't drain
properly causing an increase in pressure. If not corrected it begins to
erode cells in the retina causing increasing levels of vision
loss. This condition can be
painful. Other symptoms include lethargy, redness, enlarged eyes and
loss of appetite.

Dog with GlaucomaSource Dr. Anna Deykin/Washington State University

Initial treatment involves medication and topical ointments.
If that
doesn't control the pressure then surgery is necessary. Severe cases
require emergency care to avoid vision loss. See your veterinarian or
veterinary ophthalmologist if you even suspect
this condition in even one eye. If the condition suddenly
appears, consider the problem an emergency that requires immediate
treatment in order to avoid eye loss or blindness.

Canine
Keratoconjunctivitis Sicca (dog dry eye)

This dog eye condition is also referred to as dog dry eye or
KCS. It is commonly caused by the immune system abnormally destroying
the tear gland, causing an inadequate amount to be produced.
Without a normal amount of tears being produced, the cornea
becomes too dry, resulting in irritation and inflammation, which in
some cases leads to the appearance of a dark pigment. Other symptoms
can induce a string like mucous over the eyes.

Diagnosis of dog dry eye involves the use of a Schirmer tear
test, where the veterinarian places a thin paper in the eyes for 1
minute to measure the tears absorbed by the paper. Dogs with
dry eye are treated with cyclosporine, a medication that can help to
increase tear production.

Dog dry eye is usually a genetic problem, passed from
generation to generation. It is often seen in West Highland white
terriers, Cocker Spaniels and the Shih Tsu.

References

Washington State University

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